In a surgical procedure the distal end of a rigid tool used in the procedure, such as an endoscope, may be tracked by fixedly incorporating a location sensor in the tool. A typical surgical procedure where such a tool is used comprises an investigative ENT (Ear, Nose and Throat) procedure. The incorporated sensor may be located at the distal end of the tool; alternatively, the incorporated sensor may be located away from the distal end, towards the proximal end of the tool. In the latter case, since the incorporated sensor is in a fixed position, compensation for the displacement of the sensor from the distal end may be applied to the sensor's measured location.